Not all biologics are equal!

Background  

Although the efficacy of various biologic meshes in the abdominal reconstruction of complex ventral hernia has been shown, the performance profile of various biologic mesh scaffolds in terms of hernia-specific outcomes such as recurrence, mesh explantation, and mesh infections has not been examined.     

Not all spondylolisthesis grading instruments are reliable

Spondylolisthesis is the slippage of one vertebral body on an adjacent level, and occurs commonly at the lumbosacral junction in children. Many radiographic measurement instruments have been described to predict progression and need for intervention. We evaluated the reliability of eight common grading instruments. Four raters reviewed 30 lateral radiographs of the lumbar spine in patients with spondylolisthesis. Each rater measured each film twice, and had mean individual correlation coefficients of at least 0.76 (range, 0.76-0.91). Only three measurements had interobserver correlations greater than 0.75 (slip percentage, Meyerding's grade, and sacral inclination), which corresponded to excellent reliability. For intraobserver reliability, six measurements had correlations greater than 0.75 (all except kyphosis angle and lumbar index), indicating excellent agreement. Slip percent, Meyerding's grade, and sacral inclination had excellent interobserver agreement and intraobserver agreement.     

Not all nonpalpable breast cancers are alike.

Clinical and mammographic data of 1009 consecutive patients were correlated with histopathologic data of 1144 biopsy specimens of nonpalpable breast lesions to better define the presentation and biologic behavior of early breast cancer. Patients with malignant neoplasms (269 [24%] of 1144 specimens) were older (mean age, 62.1 years) than patients with benign lesions (mean age, 54.9 years). Furthermore, patients with invasive disease were older (mean age, 63.3 years) than patients with noninvasive disease (mean age, 58.5 years) with an overall increased risk of invasive cancer per year of 1.035. A 58% incidence of invasive cancer was detected for lesions characterized by calcifications, while the incidence of invasive cancer was 84% for isolated mass lesions (relative risk, 4.31 for masses). Isolated mammographic calcifications associated with cancer appeared in a younger population and were significantly associated with noninvasive ductal cancer. Breast cancer presenting as a mammographic mass appeared in an older group and was highly associated with the presence of invasive disease.     

Not all cementless stems are created equal: A selection algorithm

Patients, and their femurs, come in all shapes, sizes, and types. Fortunately, so do cementless femoral stems. Each surgeon should have a “go to” cementless femoral component that can address over 90% of cases. A simple approach is to separately consider (A) the part inside the bone and (B) the part outside the bone. The inner-cortical geometry (Dorr type) and bone density influence stem size (the part inside the bone) and influence femoral canal preparation. Femoral deformity or old hardware can occasionally necessitate the use of a short stem or a modular stem. Restoration of limb length and offset is a function of the neck angle and length (the part outside the bone). Undersizing of cementless stems increases the risk of aseptic loosening while restoration of limb length and offset favorably affects patient satisfaction and function.     

Not all neonatal hearts are equally protected from ischemic damage during hypothermia

Despite hypothermia, pediatric cardiac surgeons continue to experience difficulties in providing adequate myocardial protection in newborns. This study examines the effects of deep hypothermia on neonatal heart tolerance to ischemia by measuring metabolic responses and the time to onset of ischemic contracture, or "stone heart." After control right ventricular biopsy specimens were obtained, hearts of newborn pigs (n = 36) were excised and placed in temperature-regulated baths: 37.5 degrees +/- 0.5 degrees C (n = 9), 19.0 degrees +/- 0.5 degrees C (n = 14), and 12.0 degrees +/- 0.5 degrees C (n = 13). With a compliant balloon in the left ventricle to measure pressure, time to onset of ischemic contracture (greater than 2-mm Hg rise) was recorded, and sequential biopsies were done. Data indicated hypothermia significantly (p less than 0.001) prolonged time to onset of ischemic contracture from 29.5 +/- 1.7 minutes (mean +/- standard error of the mean) at normothermia to 150.0 +/- 6.4 minutes at 19 degrees C and to 283.8 +/- 46.4 minutes at 12 degrees C. Lactate buildup at 30 minutes of ischemia was significantly reduced by 70% with hypothermia. Decline in adenosine triphosphate level was significantly reduced by 50% (19 degrees C) and 75% (12 degrees C) with hypothermia. More importantly, a subgroup of hearts in each hypothermia group (n = 5 per group) was identified by 38% to 48% lower adenosine triphosphate stores before ischemia compared with the group means.(ABSTRACT TRUNCATED AT 250 WORDS)